The foreign chemicals studied include industrial products and industrial raw materials, food pigments and additives, pesticides and other traditional substances. Recently, new toxicological problems such as chloropropanol, acrylamide, mad cow disease, veterinary drug (including hormones) residues and mycotoxin pollution have appeared. In the process of food processing, sometimes a variety of pollutants can be formed, such as roast duck and mutton kebabs, and some carcinogens and mutagens (such as polycyclic aromatic hydrocarbons, heterocyclic amines, etc.) can be produced; Carcinogens (such as nitrosamines) can be produced in pickled, bacon and fish food.
In addition, it should be pointed out that excessive intake of nutrients necessary to maintain normal human physiology, such as various vitamins and essential trace elements, even fat, protein and sugar, will also cause some side effects, especially some trace elements, such as zinc, selenium and manganese. Therefore, while studying exogenous chemicals in the field of food toxicology, we should also study the toxic effects of excessive intake of essential nutrients.